In some MOSFET amplifier applications it is desirable to control the maximum output current that is sent to the load. This is of particular importance when the load is capacitive and it is desired to have a well controlled rate of change of the load voltage during transitions. A particular application with this requirement is the driving of transducers for ultrasonic imaging systems, where the harmonic content of the waveforms applied to the transducers is of primary importance. In these systems the transducer is typically a piezoelectric ceramic material, and appears predominantly as a capacitive load, with other reactive and resistive characteristics also present.
Therefore, it would be desirable to provide an improved MOSFET amplifier circuit. The improved MOSFET amplifier circuit would be able to control the maximum output current that is sent to the load of the MOSFET amplifier circuit.